1. Field of the Invention
The present invention relates to construction equipment, and more particularly to a mobile rock crushing machine. Even more particularly, the present invention relates to a self-propelled vehicle capable of crushing rock and discharging the pulverized pieces of rock into a windrow as the vehicle moves. The present invention also relates to a self-propelled rock crushing machine assembled from the existing drive unit of a conventional excavator and commercially available components. Moreover, the present invention relates to a convertible rock crushing machine having its individual components releasably secured to the machine for easy exchange or repair of the individual components, or conversion of the machine back into an excavator.
2. Description of the Prior Art
In the construction industry, there have long been used various types of crushing apparatus which pulverize rocks, stones, cement, and bricks, etc. for the purpose of reducing rubble to more conveniently sized pieces of material. The same can be said for apparatus used at quarries where it is necessary to crush rock and ore into variously sized material, which may be sorted, sold, and used according to its size. In the construction industry, however, it is of particular concern that the rock crusher be mobile or otherwise capable of transport. For example, it may be necessary to relocate a rock crusher from one road construction site to another. To accommodate this need, the prior art contains numerous examples of mobile or transportable rock crushers.
U.S. Pat. No. 2,117,300, which issued to John Corser on May 17, 1938, discloses a rock crushing machine that separates finely crushed material (i.e., sand) for collection and recycles larger material for repeated crushing. The Corser apparatus utilizes a pair of crushing elements for differently sized material, whereby both crushing elements deliver the crushed material to a system of conveyors that returns the crushed material to the single separating device. Finely crushed material passes through the separator and is delivered to the output location, whereas larger material is continuously recycled until it is finely crushed.
U.S. Pat. No. 2,276,333, which issued to Melvin Ovestrud on Mar. 17, 1942, discloses an apparatus and method for crushing and segregating materials. The apparatus disclosed in the Ovestrud patent is disposed particularly for the production of fine rock material having a size of approximately between one-quarter and one-half inch in diameter. The Ovestrud apparatus uses a plurality of crushing elements, fed by various conveyer systems, that operate in succession to reduce the size of rock and separate the same according to its size.
U.S. Pat. Nos. 3,841,570 and 3,927,839, which issued to John N. Quinn on Oct. 15, 1974, and Dec. 23, 1975, respectively, disclose a rock crushing plant and a crushing apparatus. Each discloses a rock crushing apparatus that contains a pre-crushing separating unit that separates rock according to its size. Material of the final product size and sand are removed from the apparatus, whereas larger rocks of different sizes are segregated and separately transported over various conveyor systems. A primary crusher is used following the initial segregation to reduce larger rocks, and material is further segregated before entering the secondary crusher. At the secondary crusher, material output of finished size is discharged by conveyor and material which remains too large is recycled for repeated passage through the secondary crusher.
Each of the above-listed patents discloses a rock crushing apparatus that is transportable by sets of wheels located thereon. The apparatus, however, are not capable of self-powered transportation. Instead, they require another vehicle to tow them to the construction site, where they remain stationary during use. Furthermore, each of the above-listed apparatus utilizes repeated crushing cycles to reduce rock size to within the range of finely crushed material or sand. Thus, an elaborate conveyor system is necessary to ensure proper crushing of the rock.
Because modern construction sites may be extremely large, such as highway construction sites, it is preferable to have a rock crusher that is not only transportable between sites, but also mobile at the construction site. Having a rock crusher that is mobile at the construction site saves time and obviates the need for numerous trucks to haul material to and from the rock crusher. By providing a rock crusher that is mobile at the construction site, crushed material may be produced where it will later be needed. Thus, it is extremely advantageous to provide a rock crusher of the type that is mobile at the construction site.
An alternative form of rock crusher is the type disclosed in U.S. Pat. No. 4,607,799, which issued to Bobby R. Currie on Aug. 26, 1986. The mobile stone crusher disclosed in Currie is disposed for use in connection with a track loader, which moves the stone crusher along the ground to crush rocks and other debris located in its path. To be used at a construction site necessarily requires prior alignment of material to be crushed, which generally is accomplished with the use of a road grader. Moreover, because the crusher is carried over the ground, the mobile stone crusher is not well adapted for use over rough terrain.
A transportable crusher unit is disclosed in U.S. Pat. No. 5,161,744, which issued to Gunther-Dietmar Schoop on Nov. 10, 1992. The transportable crusher unit comprises a frame that supports a crusher unit, separable crawler elements removably attached to the frame, and a plurality of lift jacks integral with the frame. When the crusher unit is to be moved the lift jacks are raised to elevate the frame, and the crawler elements are separated from the frame so that a flatbed trailer may be driven beneath the frame. In this way the crusher unit may be transported without the need for special vehicles. While the crusher unit is at a site, the crawler elements provide necessary traction to allow for some mobility over the uneven terrain. Because the Schoop et al. apparatus utilizes two separate and distinct sets of crawler elements to drive the device and the frame is relatively low in the region between the two sets of crawler elements, the crusher unit is not readily adapted for a significant amount of travel at the construction site. Instead the crusher unit may be maneuvered into position using the driven crawler elements, and then the crusher unit may rest in place during operation. A second embodiment of the Schoop et al. crusher unit is placed onto support trestles where it remains in a fixed location during operation.
U.S. Pat. No. 5,460,332, which issued to Dietmar Frick on Oct. 24, 1995, discloses a mobile crusher apparatus capable of self-propelled movement on crawler elements. The crusher comprises a hopper for receiving rock or debris, and a crusher having a discharge conveyor. The hopper and discharge conveyor are pivotally mounted for hydraulic reciprocation relative to the crusher, so that the hopper and discharge conveyor sections may be hydraulically lowered to place sets of wheels thereon onto the ground. This action elevates the crawler elements upwardly from the ground. A tractor may hitch to the lowered hopper section to haul the rock crusher on the highway. While the system for converting the Frick crusher into a transportable crusher is described in detail, operation of the crusher is not adequately described in detail. It is not apparent from the description whether the crusher is of the type that is disposed for crushing material while moving over the uneven terrain at a construction site to provide a continuous crushing operation.
U.S. Pat. No. 5,476,227, which issued to Yukio Tamura et al. on Dec. 19, 1995, discloses a self propelled crushing machine. The crushing machine has a pair of crawler elements for transportation, and a hopper and crusher strategically located relative to the engine to avoid an excessive height of the crushing machine. Specifically, the engine is located at one end of the chassis, with the hopper located at the other end, and the crusher located intermediate the engine and hopper. A discharge conveyor collects crushed material from the outlet of the crusher, located generally at the middle of the machine, and carries it forwardly from the machine.
Because the greatest concern with the Tamura et al. crushing machine is its overall height, the placement of the discharge conveyor beneath the platform supporting the crusher requires thee conveyor to lie between the crawler mechanism. This severely limits the height clearance for the underside of the machinery. Construction sites typically have rough terrain that necessarily requires heavy-duty drive mechanisms and high ground clearance. While the Tamura et al. apparatus may travel at a construction site, it is particularly designed for simplified transportation between construction sites. By limiting the ground clearance of the machine, it is not particularly suited for movement during the crushing process. This is evident from a Komatsu advertising brochure for the BR300J Mobile Crusher, where the discharge conveyor is shown in a position that is substantially lower than the claimed ground clearance. It is also evident from the fact that the machine disclosed in the patent does not provide the operator with a protected operating station (i.e., cage), which normally is mandated for vehicles that move while performing operations.
Modern construction codes generally mandate specifications for the size of material used in backfill operations such as, for example, "six-minus" for backfill matter that is six inches or smaller, or "three-minus" for backfill material that is three inches or smaller. There is a need in the industry for a machine that can produce finish backfill that meets specifications for particulate size and also has a sufficient moisture content to minimize sinking. Modern construction codes also typically limit the amount and content of material which may be buried. Large rocks, which typically cannot be buried, usually result in an overburden with large material and a contrasting need for sufficient undersize material. When there is a need for undersize material and a burden of oversize material, such materials historically have been hauled to or away from the construction site, respectively. Thus, a rock crushing machine that can produce finish backfill at the precise location where it is needed would save a considerable amount of time and money in conducting operations at construction sites.
None of the above prior art discloses a rock crushing machine that specifically is designed and disposed for crushing rock and other debris while the machine is moving, and discharging the crushed material into a windrow for later use. Furthermore, none of the prior art discloses a rock crushing machine capable of producing finish backfill material that has a sufficient moisture content. The prior art provides rock crushing apparatus that are both transportable over the highway and to some extent mobile at a construction site. However, there is a need for a rock crushing machine that may provide crushed material into a continuous windrow as the crushing machine propels itself over the construction terrain.
Furthermore, none of the above prior art provides a rock crushing machine having detachable components. While the crawler elements in the Schoop et al. patent disclosed above were detachable, none of the major components of the crushing machine (i.e., the hopper, the feed conveyors, the crushing devices, and discharge conveyors, etc.) were detachable for replacement or removal from the device. Finally, none of the above noted prior art specifically discusses variable speed control for the drive mechanisms which operate the different components of the rock crushing machines.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.